
#ifndef __json_value_serializer_h__
#define __json_value_serializer_h__

#pragma once

#include <string>

#include "base/basic_types.h"
#include "base/file_path.h"
#include "base/value.h"

class JSONStringValueSerializer : public base::ValueSerializer
{
public:
    // json_string is the string that will be source of the deserialization
    // or the destination of the serialization.  The caller of the constructor
    // retains ownership of the string.
    explicit JSONStringValueSerializer(std::string* json_string)
        : json_string_(json_string),
        initialized_with_const_string_(false),
        pretty_print_(false),
        allow_trailing_comma_(false) {}

    // This version allows initialization with a const string reference for
    // deserialization only.
    explicit JSONStringValueSerializer(const std::string& json_string)
        : json_string_(&const_cast<std::string&>(json_string)),
        initialized_with_const_string_(true),
        pretty_print_(false),
        allow_trailing_comma_(false) {}

    virtual ~JSONStringValueSerializer();

    // Attempt to serialize the data structure represented by Value into
    // JSON.  If the return value is true, the result will have been written
    // into the string passed into the constructor.
    virtual bool Serialize(const base::Value& root);

    // Attempt to deserialize the data structure encoded in the string passed
    // in to the constructor into a structure of Value objects.  If the return
    // value is NULL, and if |error_code| is non-null, |error_code| will
    // contain an integer error code (either JsonFileError or JsonParseError).
    // If |error_message| is non-null, it will be filled in with a formatted
    // error message including the location of the error if appropriate.
    // The caller takes ownership of the returned value.
    virtual base::Value* Deserialize(int* error_code, std::string* error_message);

    void set_pretty_print(bool new_value) { pretty_print_ = new_value; }
    bool pretty_print() { return pretty_print_; }

    void set_allow_trailing_comma(bool new_value)
    {
        allow_trailing_comma_ = new_value;
    }

private:
    std::string* json_string_;
    bool initialized_with_const_string_;
    bool pretty_print_;  // If true, serialization will span multiple lines.
    // If true, deserialization will allow trailing commas.
    bool allow_trailing_comma_;

    DISALLOW_COPY_AND_ASSIGN(JSONStringValueSerializer);
};

class JSONFileValueSerializer : public base::ValueSerializer
{
public:
    // json_file_patch is the path of a file that will be source of the
    // deserialization or the destination of the serialization.
    // When deserializing, the file should exist, but when serializing, the
    // serializer will attempt to create the file at the specified location.
    explicit JSONFileValueSerializer(const FilePath& json_file_path)
        : json_file_path_(json_file_path) {}

    virtual ~JSONFileValueSerializer() {}

    // DO NOT USE except in unit tests to verify the file was written properly.
    // We should never serialize directly to a file since this will block the
    // thread. Instead, serialize to a string and write to the file you want on
    // the file thread.
    //
    // Attempt to serialize the data structure represented by Value into
    // JSON.  If the return value is true, the result will have been written
    // into the file whose name was passed into the constructor.
    virtual bool Serialize(const base::Value& root);

    // Attempt to deserialize the data structure encoded in the file passed
    // in to the constructor into a structure of Value objects.  If the return
    // value is NULL, and if |error_code| is non-null, |error_code| will
    // contain an integer error code (either JsonFileError or JsonParseError).
    // If |error_message| is non-null, it will be filled in with a formatted
    // error message including the location of the error if appropriate.
    // The caller takes ownership of the returned value.
    virtual base::Value* Deserialize(int* error_code, std::string* error_message);

    // This enum is designed to safely overlap with JSONReader::JsonParseError.
    enum JsonFileError
    {
        JSON_NO_ERROR = 0,
        JSON_ACCESS_DENIED = 1000,
        JSON_CANNOT_READ_FILE,
        JSON_FILE_LOCKED,
        JSON_NO_SUCH_FILE
    };

    // File-specific error messages that can be returned.
    static const char* kAccessDenied;
    static const char* kCannotReadFile;
    static const char* kFileLocked;
    static const char* kNoSuchFile;

    // Convert an error code into an error message.  |error_code| is assumed to
    // be a JsonFileError.
    static const char* GetErrorMessageForCode(int error_code);

private:
    FilePath json_file_path_;

    // A wrapper for file_util::ReadFileToString which returns a non-zero
    // JsonFileError if there were file errors.
    int ReadFileToString(std::string* json_string);

    DISALLOW_IMPLICIT_CONSTRUCTORS(JSONFileValueSerializer);
};

#endif //__json_value_serializer_h__